HieraChain v0.0.1.dev4 - Security Hardening

Pre-release Warning: This is a development preview and is not intended for production use. APIs may change without notice.

What's New

Secure Logging: Added secure_logging.py and sanitization.py utilities to prevent sensitive data leakage in logs (d4d645d).
API Authentication: Enhanced auth status logging on startup, refined logging levels (b9fba70).
Error Handling: Added RecursionError handler to prevent JSON bomb DoS attacks (7922aca).
Payload Limits: Implemented 5MB payload size limit middleware (7922aca).
Security Headers: Enhanced security headers (X-Content-Type-Options, X-Frame-Options, CSP, Cache-Control) (27d700b).
Rate Limiting: Added in-memory rate limiter middleware with configurable limits (f442b84).
Hash Algorithm: Replaced MD5 with SHA256 for improved security (7d79c98).

CVE-2024-23342 (HIGH): Removed unused python-jose dependency which pulled in vulnerable ecdsa package with unfixable Minerva timing attack vulnerability (134f97b).

Production Settings: Enhanced security defaults for production environment including mandatory AUTH, restricted CORS, HSTS, and rate limiting (a63501f).
Configurable API Host: API host now configurable via HRC_API_HOST environment variable (44a72d3).
Connection Handling: Improved connection handling with keep-alive timeout and concurrency limits (f442b84).

Probe Scripts: Added security probe scripts for vulnerability detection (4f17875):
- http_headers_probe.py - Security headers verification
- auth_bypass_probe.py - Authentication bypass testing
- input_fuzzer.py - Input validation testing
- api_key_edge_cases_probe.py - API key handling edge cases
- log_level_test.py - LOG_LEVEL disclosure testing
- And more...
SAST Integration: Added bandit and pip-audit to development dependencies for static analysis (551526f).

Secure Endpoints: Integrated secure logging and sanitization for v2 API endpoints (ab3ce70).

File	Changes	Commit
`hierachain/security/secure_logging.py`	Add secure logging utilities	`d4d645d`
`hierachain/security/sanitization.py`	Add sanitization utilities	`d4d645d`
`hierachain/config/settings.py`	Enhance security/performance settings, configurable API host	`a63501f`](`a63501f`), 44a72d3
`hierachain/api/server.py`	Security headers, recursion error handler, payload limit, rate limiter	27d700b, `7922aca`, `f442b84`
`hierachain/api/v2/endpoints.py`	Integrate secure logging and sanitization	[`ab3ce70`
`requirements.txt`	Remove `python-jose` (CVE-2024-23342)	`134f97b`
`pyproject.toml`	Remove `python-jose`, add `bandit` and `pip-audit`	`134f97b`
`scripts/security/*`	Add probe scripts for vulnerability detection	`4f17875`

Tool	Result
Bandit (SAST)	✅ CLEAN - 0 issues in 23,236 lines of code
pip-audit (SCA)	✅ CLEAN - All vulnerabilities resolved

Not production-ready
Documentation still in progress
Some security probe scripts require server to be running with AUTH_ENABLED=True for full testing